lisp/options.el

   1 ;;; options.el --- edit Options command for Emacs.
   2
   3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   4
   5 ;; This file is part of GNU Emacs.
   6
   7 ;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation; either version 1, or (at your option)
  10 ;; any later version.
  11
  12 ;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  19 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21
  22 ;;;###autoload
  23 (defun list-options ()
  24   "Display a list of Emacs user options, with values and documentation."
  25   (interactive)
  26   (save-excursion
  27     (set-buffer (get-buffer-create "*List Options*"))
  28     (Edit-options-mode))
  29   (with-output-to-temp-buffer "*List Options*"
  30     (let (vars)
  31       (mapatoms (function (lambda (sym)
  32                             (if (user-variable-p sym)
  33                                 (setq vars (cons sym vars))))))
  34       (setq vars (sort vars 'string-lessp))
  35       (while vars
  36         (let ((sym (car vars)))
  37           (princ ";; ")
  38           (prin1 sym)
  39           (princ ":\n\t")
  40           (prin1 (symbol-value sym))
  41           (terpri)
  42           (princ (substitute-command-keys
  43                   (documentation-property sym 'variable-documentation)))
  44           (princ "\n;;\n"))
  45         (setq vars (cdr vars))))))
  46
  47 ;;;###autoload
  48 (defun edit-options ()
  49   "Edit a list of Emacs user option values.
  50 Selects a buffer containing such a list,
  51 in which there are commands to set the option values.
  52 Type \\[describe-mode] in that buffer for a list of commands."
  53   (interactive)
  54   (list-options)
  55   (pop-to-buffer "*List Options*"))
  56
  57 (defvar Edit-options-mode-map
  58   (let ((map (make-keymap)))
  59     (define-key map "s" 'Edit-options-set)
  60     (define-key map "x" 'Edit-options-toggle)
  61     (define-key map "1" 'Edit-options-t)
  62     (define-key map "0" 'Edit-options-nil)
  63     (define-key map "p" 'backward-paragraph)
  64     (define-key map " " 'forward-paragraph)
  65     (define-key map "n" 'forward-paragraph)
  66     map)
  67   "")
  68
  69 ;; Edit Options mode is suitable only for specially formatted data.
  70 (put 'Edit-options-mode 'mode-class 'special)
  71
  72 (defun Edit-options-mode ()
  73   "\\<Edit-options-mode-map>\
  74 Major mode for editing Emacs user option settings.
  75 Special commands are:
  76 \\[Edit-options-set] -- set variable point points at.  New value read using minibuffer.
  77 \\[Edit-options-toggle] -- toggle variable, t -> nil, nil -> t.
  78 \\[Edit-options-t] -- set variable to t.
  79 \\[Edit-options-nil] -- set variable to nil.
  80 Changed values made by these commands take effect immediately.
  81
  82 Each variable description is a paragraph.
  83 For convenience, the characters \\[backward-paragraph] and \\[forward-paragraph] move back and forward by paragraphs."
  84   (kill-all-local-variables)
  85   (set-syntax-table emacs-lisp-mode-syntax-table)
  86   (use-local-map Edit-options-mode-map)
  87   (make-local-variable 'paragraph-separate)
  88   (setq paragraph-separate "[^\^@-\^?]")
  89   (make-local-variable 'paragraph-start)
  90   (setq paragraph-start "^\t")
  91   (setq truncate-lines t)
  92   (setq major-mode 'Edit-options-mode)
  93   (setq mode-name "Options")
  94   (run-hooks 'Edit-options-mode-hook))
  95
  96 (defun Edit-options-set () (interactive)
  97   (Edit-options-modify
  98    '(lambda (var) (eval-minibuffer (concat "New " (symbol-name var) ": ")))))
  99
 100 (defun Edit-options-toggle () (interactive)
 101   (Edit-options-modify '(lambda (var) (not (symbol-value var)))))
 102
 103 (defun Edit-options-t () (interactive)
 104   (Edit-options-modify '(lambda (var) t)))
 105
 106 (defun Edit-options-nil () (interactive)
 107   (Edit-options-modify '(lambda (var) nil)))
 108
 109 (defun Edit-options-modify (modfun)
 110   (save-excursion
 111    (let (var pos)
 112      (re-search-backward "^;; \\|\\`")
 113      (forward-char 3)
 114      (setq pos (point))
 115      (save-restriction
 116        (narrow-to-region pos (progn (end-of-line) (1- (point))))
 117        (goto-char pos)
 118        (setq var (read (current-buffer))))
 119      (goto-char pos)
 120      (forward-line 1)
 121      (forward-char 1)
 122      (save-excursion
 123        (set var (funcall modfun var)))
 124      (kill-sexp 1)
 125      (prin1 (symbol-value var) (current-buffer)))))
 126
 127 ;;; options.el ends here